Mechanism for operating car-brakes.



H. DIXON. MECHANISM FOR OPERATING GAR BRAKES.

APPLICATION FILED JUNE 1,1908.

1 925,466, Patented J'un'e22,1909.

a umum- 4 8 I I 1 v 9 7 FIG.- 2.

I "(I TNIE,ISSES v //v VENITOR.

H. DIXON. 4 V MEGHANISM FO R OPERATING GAR BRAK 2 SHEETS-SHEET 2.

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HENRY QIXON, 0F BALMY BEACH, ONTARIO, CANADA, ASSIGNOR TO JOHN LANGFORD PEACO CK, OF BUFF,ALO, NEW YORK.

IIECHANISM FOR OPERATING OABJ-BRAKEB.

I Application filed June 1, 1908. Serial No. 435,914.

hicles, and particularly to that class in which the brake-post or handle operates with a v variable levera e through the medium of a compensating evice, during the application of the brake; and theobj ect of the invention is to make'more eiiicient the present handbrake system of electrically propelled or trolley cars, and to enable the operator to apply the brake with suflicient force to cause cessation of movement in a comparatively short distance, with a minimum expenditure of energy, and to eliminate the objectionable feature of additional turns of the brake-post over and above that found practical for rapid braking of carsf Characteristic of the-present invention is the embodiment of a stop-motion device, whereby the, lost motion due to backlash is eliminated in the brake-operating mechanism and a fixed or positive stop provided, to limit the rotation of the o crating elements in the direction of unwin ing,'while within the range of the capacity of the chain or cable drum its rotation in the direction of winding is unimpeded. I

The invention'consists in part of the incorporation of a brake-actuating spiinljfimff constluctcd in such a manner as to set up a differential leverage of increasing magnitude relatively proportionate to the applied brain ing force, during the rotation of the initial power receiving brake-post, and certain details of construction, as hereinafter set forth and illustrated in the accompanying drawings, in'which similar figures of reference refer to like parts throughout.

Figures 1 and 2 are views in top plan and side elevation, respectively, of the improved In chanism for operating car brakes. Fig. 3 is a vertical longitudinal sectional view of the device shown in Figs. 1 and 2, .with a portion of the actuatin elements shown in elevation; and Figs. 4 an 5 are inverted plan views of Specification 01. Letters Patent.

"thereon Patented tim 22, 1909.

the pinion and gear showing the relative positlons of the contact arms of the stopmotion device.

The frame or bracket 1 is preferably cast in one piece and rovided with a series of lateral lugs 2, three 0 which are sufficient and found to be advantageous in insuring at all times a true and rigid support. In some instances, it is found essential to 'ournal the primal actuating medium or brake- 0st on' the outside of the dash, and with t s end in view, provision is made in theconstruction of the frame 'to admit of its projecting beyond the front of the dash when bolted or otherwise secured to the underside 'of the platform of the car. The present brake-post and its appurtenances can be employed with but a slight modification of its lower extremity. Within the frame 1 are ivotally mounted the actuating elements of? the brake-operating device.

The lower extremity of the brake-post 3 is journaled in the upper and lower ortions of the frame and serves as the spin 10 for the pinion 4, carried fast thereon. In alinement -with and parallel of the s indie or brake-post 3 is a'vertically dispose stud 5, terminally fixed in the upper and lower portions of the frame and secured in a manner to insure against its displacement, for which purpose there is formed a shoulder on the lower end of the stud, and below said shoulder and subjacent to the frame provision is made for the reception of the cotter pin 6, as shown.

lwoted upon the stud 5 and adapted to revolve freely thereon is a spur-gear 7-,.in mesh with'the aforesaidpinion 4 and integral with the spiral brake-chain drum 8, also revolving The ratio of the spur-gear 7 an pinion 4 is relatively proportionate to the capacity of the drum and the leverage .desired during the angular movement of the brake-post 3. upper portion of the frame surrounding the same is reeessed to form a chamber 12, which serves as a reservoir for lubricant for the )arts which rotate upon the aforesaid stud. he drum 8 upon which the brake-chain 9 is we l is a tapering spiral adapted to merge into a cylindrical portion 8, as shown.

The efiiciency of a device of this nature is in a great measure dependent upon the. rovision m'ade therein for taking up the s aok of the brake-actuating mechanism of the car with the lowest practical turning moment Directly above the stud 5 the .acterisiic feature set forth'in the preamble of this specification.

By referring to l igs14 and 5 it will be seen that, commencing at the greatest radius of f the drum 9, at which )oint the chain 9 is 5 made last, the slack ol' the brake-chain is i with said gear and adapted to'operate with a.

rapidly taken up by the major portion of the drum gradually diminishing with an increasing purchase, the maximum being attained when that portion of the drum 8 is reached wherein the diameter ceases to decrease.

ing with said gear arntpinion to Form a stopmotion device, a brake-actuating drum interacting with said gear, and a brake-post adapted to operate said gear through the medium of said pinion.

2. in a brake-actuating mechanism, the combination with a gear and its actuating pinion, of interacting contact arms rotatable with said gear and pinion. to term a stop-motion device, a brake-chain drum interacting variable leverage, and a brake-post adapted to operate said gear through the medium of 1 saidpinion.

llpon the latter or cylindrical part oi the 1 drum may be wound additional chai'n while retaining the maximum leverage and with.- out further increasing the turning momentper unit length of chain. Subjacent 'to the plane of the train of gears are radial arms 10 and 1]., v. hich project sulliciently beyond the pitch circles to cause their extremities to engage each other and serve as a limiting-stop to impede further movement of the aforesaid gears. These radial or contact arms 10 and I). In a ln'ake-actuating mechanism, the combination with a gear and its actuating pinion, ol' rotatable. contact arms interacting with said gear and pinion to form a stop-motion device, a, brake-actuating spiral drum integral with said gear and adapted to oper ate vwith a variable leverage, and a br kepost. interacting with said pinion, for the-purpose hereinbehire forth.

4. in a ln'ake-actuatin mechanism the combination with a pinion having a contact arm, of a lwake-actuating drum and gear ii are integral with the pinion 4 and spurgear 7, respectively, and are adapted to meet n a lix d position relatively to that ol' the drum 8, as shown in Fig; 4, and arrest l'nrther ate said gear through the medium of said movement in the direction of in. .vinding when the chain ceases to lap the drum. In this position or point of rest the brake is fully released. Further movement in the direction indicated by arrow in Fig. 4, would yield unnecessary slack and materially atliect in operation the etlieiency of "the device. Within the range of the proportions adaptable for the gears of this device,'theratio of their angular velocities is such that, from. the

oint of rest and during the application of the rake, the drum may in the course of winding-the chain thereon, be rotated. (in the direction. indicated by arrow in Figf5,) in excess of its capacity. before the radial arms again engage each other. in the present device, the usual. or lessexpensive form of hearing is adapted; but should it be found desirable to reduce thefri tion oi the o crating elements to a minim m, and particu arly the parts subjected to a forceful strain, it is only a mechanical expedient to substitute there for a. suitable term of 'roller--bearing. The latter form of bearing is preferable when the cost of construction is not an important conl havin" a like arm. said arms ada'ite'd to engage .aeh other and limit the movement of the aforesaid drum in the direction of unwinding, and a bral e-post adapted to operpinion.

In a bralm-actuating mechanism, the combination with a brake-actuating drum and gear, of a radial arm an integral part of said drum and gear, a inion in mesh with sa d gear and having a ilc radial arm, said arms adapted to engage each other and limit the movement of the aforesaid drum in the direction of unwindhig, and a brake-post adapted to operate raid gear through the medium of said inion, for the purpose hereinbet'ore set forth.

6. in a brake-actuating mechanism, the cornbirration with a pinion havin a radial contact arm, of a brake-actuating spiral drum and gear having a like arm, said. arms adapted to engage each other and form a stop-motion device, a brake-chain operating with a variable leverage from the spiral and concentric periphery of said drum, and a l 1'al epost adapted to operate said gear through the medium of said pinion, substantially as shown and for the purpose set forth.

in testimony whereof I have, signed my name to this specification in the"-presmce of 1 two subscribing witnesses.

Witnesses:

S. It. lCAnLn, (J. W. Avnm'. 

